Advanced base stations can be configured in many ways for optimizing coverage and capacity; base station radio architectures may for example comprise several more or less identical antenna units, i.e. antennas and radio that are placed in one common antenna unit that can be used as a building block. Such an antenna unit may for example be equipped with two separate radios; one for each polarization. Placing many such antenna unit building blocks together can facilitate modular site configuration with scalable properties, and the configuration can be referred to as a base station constellation.
Another issue in cellular networks is when multiple active units are placed high up in a mast, via optical or electrical I/Q-links (also known as CPRI (Common Public Radio Interface) links, while the base band processing is located on ground.
By using antenna units as common building block components, a base station system can be setup with different number of radiating elements for different coverage and capacity scenarios. This building block can then be used to create different types of base stations suitable for different scenarios, such as Wide Area, Medium Range or Local Area. Also the antenna aperture can be designed to fit special coverage scenarios, such as high building, meaning that the antenna aperture can be configured as outspread in horizontal or vertical domain or both. A system is then configured by using one or more antenna units to facilitate MIMO (Multiple Input Multiple Output) and/or cell-specific beam-forming.
Cell-specific beam forming is created by calculating phase and amplitude weight for each radiating element. The location and orientation of each individual antenna element, or at least each antenna unit, is needed by the baseband processing when calculating the array excitation required for cell-specific beam-forming. The relative location of each radiating element can be represented by a position matrix, where each element location (x,y,z) is stored in a common matrix with dimension N×3, where N is the total number of radiating elements in the base station.
The relative location of the antenna units in a base station constellation is relevant as information for baseband processing mentioned above, and also for OSS (Operational Support System). For OSS, the information can be used to visualize how the base station is configured.
In current systems, the location matrix is known by the design, when all radiating elements are included. However, for systems created in a modular fashion using antenna units as building blocks according to the above, the concept requires that the system is configured with correct setup information, where location of each element is available together with orientation of each element with respect to earth gravity.
There is thus a need to find the correct mapping of signals, where the installation maps to baseband ports in an efficient and reliable manner. This need is also relevant for legacy base stations with traditional feeder cables.